Foreword

As usualy, the author is supposed to say that this isn't the best way of modeling/sculpting and all that, and well I suppose it isnt, but it gets you around ;D This tutorial is not for total beginners, you should have some experience to make it through it. I have for example not explained where to find the different tools.

As you progress through the tutorial, you'll notice that i have set the images up in 3 or 4 steps. Here you might have to use your own skills to find out how to find the solutions, but I'll explain it as good as I can. To avoid confusion, these images have numbers in the corners. Hope you'll find my tutorial helpful :)

Setting up the workspace

Start off by creating a plane in the Left viewport. Set length to 260 and width to 165, and both length and width segs to 1. The chosen ratio fits the sketch pretty well.
Select a free slot in the material editor and add the sketch.jpg to its diffuse channel. Make the map visible in viewport and apply the material to the plane. move the plane to x=0, Y=30 and Z=0 (World) so that the center of the character will be in the center of the coordinate system.
Also turn off the Grid in the perspective and left viewports, turn on Smooth + Highlight, and Edged Faces. Right click the plane object and bring up the properties dialog. Check the Frozen box and uncheck the Show Frozen In Grey box. Now the sketch wont interfere with what we do in the viewports.

Lets get started

We'll do the legs first. Create a 10 sided cylinder with 7 height segments in the top viewport. I set the radius to 17 and moved around in the left viewport so it overlapped the leg on the sketch. Enable Display As See-Through Toggle, this way it is easy to see the sketch when youre working on the model.

Convert the cylinder to an Editable Mesh, or Editable Poly if that floats your boat. I am not that familiar with edit poly, so some functions may vary. I suggest you use edit mesh for now. In (Element) mode, select the leg and move it about 30 units to either side in the front viewport. In (Vertex) mode, use the scale, move and rotate tools to make the pants look somewhat like this. Start on the top and work with the verts segment by segment downwards. Remember to scale on all three axes so the pants wont look even in the front viewport. Delete the top and bottom cap polygons.

Now we're gonna make the crotch area. Create a new 12 sided cylinder with 2 height segments in the top viewport. Use the Move Transform Type-In to center it over the belt on the sketch. I used the coordinates X = 0, Y = 0 and Z = -18. Scale it about 140% on the X-axis (Top or Left viewport) Convert it to an editable mesh, delete the left side polygons and the top and bottom polygons. Enable See-Through Toggle. Add an FFD (box) modifier to the stack and set its number of points to L=3, W=2 and H=2, and adjust the top of the pants to the sketch by moving the control points like on the image.

Now lets connect the two parts. First move the top of the leg towards the new soon-to-be crotch. Highlight the leg mesh and select the 2 top segments in (Polygon) mode. We dont want to break the topology on the bottom of the pants, because we are to make shoes there and they need (on this model at least) a perfect symetrical circle to be extruded from. But we'll take that later. With the polygons selected, turn on Soft Selection. Set Falloff to 40 units. With the polygons selected, add an FFD 2x2 modifier to the stack. When you move the control points, only the top parts of the mesh will be affected, and the degree they are affected decrease as you go down the mesh. This renders the bottom unchanged. Add an edit mesh modifier to the stack, re-convert it to an editable mesh or use the collapse button in he utilities menu. I suggest you collapse the stack from time to time.

Use the attach button to merge the two meshes into one. Highlight the 5 vertice pairs on the outer side of the hip and weld them together two by two as shown on the picture.

The next part is a bit tricky. Since we used a 10 sided cylinder and have connected 5 of the verts to the newer piece of mesh, there are 5 left. Move the vertices on the inside of the crotch down a bit in the Front viewport: Then select all the 5 remaining edges and shift drag them towards the center of the X-axis and up a bit. Use the Scale Transform Type-In to scale them down to 0% on the X-axis. Use the Move Transform Type-In to center them on the X-axis as well.

Weld the two vertices on the front and the two on the back where the mesh leaks

USelect both the original and the instanced mesh and highlight the top Edges. Shift drag them up a bit and use the Scale tool (Select and Non-Uniform) to scale them in a bit. Highlight all polygons and in the Surface Properties dialog set their Material ID to 1 and Smoothing Group to 1. The Pants are now finished. In the Material Editor, select a new slot, set its diffuse color to something bright brown/yellow and click the "2-sided" box. I used the values R= 200, B= 190 and G=180. Apply the new material to both pant objects.Strike "8" to bring up the Environment and Effects dialog. Set the background color to bright grey. R=190, B=190 and G=190 works fine.

Set the Referance Coordinate System to Local and Shift-drag the 10 edges on the bottom of the pants down. Scale them out on all 3 axes while trying to maintain the shape of the shoe on the sketch. Shift-drag one more time, but do not scale. Select the vertices (remember we are now working on an object with two sides) as shown on the picture (1) and chamfer them about 6 units (2). Target-weld the top of the three new vertices to the vertice above (3). This is best done in any other than the Left viewport.

We'll continue the shoe by Shift-dragging the edges and scaling them. Also manually move the vertices on the front of the shoe to fit the sketch. Build the polygons under it manually. Rotate all the shoe polys about 10 degrees outwards on the Z-axis in the top viewport while soft selection is turned off. A radius of 40 works fine sow the leg wont look twisted and ugly. Set the two first segments of polygons to Smoothing Group 2. This seperated the shoe from the pants and also makes a rough edge where the dark brown meets the light brown on the sketch.

Ok now we got the shoes and pants nailed down pretty well, let's move on to the upperbody. We're gonna use the same techniques as before, shift-dragging edges, scaling and moving vertices where it's needed. Use the circle of edges on the top of the pants to extrude out the stommack and chest. Shift-Drag from both the original and the instanced mesh. Rotate and scale in and out to fit the sketch. 7 segments will do. Set the two first to Smooth Group 2 to seperate the for some reason bare stommack from the pants and the shirt. Dont worry about the jacket yet.

Next step is to make the arm, place it in the desired location and clean up the mesh in the shoulder area. Start by making a 10-sided cylinder in the top viewport and make it somilar to the referance image. You'll have to rotate it 90 egrees on the Z-axis before you start for it to fit my evil scheme >' > Also scale the arm down to 90% on the X-axis to so it wont looks so fat.